Electrolytic device



J. L. coLLnNs ELECTROLYTIC DEVICE Filed Jan. 10. 1938 nub May 21, 19409 INVENTOR. JOSEPH L. COLLLNS BY 491771 ATTORNEYS Patented May 21, 1940 PATENT. OFFICE ELECTROLYTIC DEVICE Joseph L. Collins, North Adams, Mass., assignor to Slime Specialties Company, North Adams Mass a corporation of Massachusetts Application January 10, 1938, Serial No. 184,324 4 Claims, (Cl. 175-315) The present invention relates to electrolytic devices, and more particularly to novel spacing or separating means to mechanically separate and insulate from each other the electrodes of such devices.

My invention will be described with reference to electrolytic condensers having a mobile electrolyte, for which it is of particular importance.

As is well known, electrolytic condensers having a mobile (fluid or semi-fluid) electrolyte comprise in their usual form one or more filmed elecerably less than'the height of the container, and

frequently 'not more than hall of it. This is for several reasons: First, there has to be a sufllciently high electrolyte-filled space on top of the anode to insure complete immersion thereof even when the condenser is tilted from its vertical position; in addition due allowance must be madefor loss of electrolyte due to its evaporation in operation. Furthermore, to prevent the burst ing or the container, should the condenser be exposed to freezing temperatures, there has to be an electrolyte free space above theelectrolyte level.-

The most'widely used spacers are thin sheets of Celluloid, hard rubber or like material, cylindrically encircling the anode assembly and separating it from the cathode-container.

To prevent displacement oi the spacer, which might occur if the condenser is subjected to- 1 shocks, or is turned upside down, etc., the spacers have been given the same height as the container so as to abut against both end faces of the container. Consequently a great part, frequently as much as 50% of the spacer material, was substantially wasted except to the extent as it served as positioning means. As the cost of the spacer in present-day condensers represents an important portion of the total cost of the condenser, it is one of the objects of my invention to avoid such waste of spaced material.

Such prior spacers had the further drawback of providing no insulationv between the anode and the container bottom, which often resulted in the condensers becoming inoperative because of accidental contact between the anode and the container, brought about, for example, by the sag ing of the anode or byits displacement by outside forces transmitted through the anode riser.

5 Prior constructions, to prevent such short circuits, required either placing an additional in sulating washer between the anode and the container bottom, or forming the insulating spacer as a sheath entirely surrounding the anode except-for the projecting anode riser. As these constructions required additional insulating material they further increased. the cost or the condenser.

A further object of my invention is therefore to provide a spacer which prevents accidental ,contact between the anode and container bottom and which does not require additional spacer material.

In accordance with the'invention, for the separation of the anode from the cathode I usea spacer consisting of a thin sheet of insulating material surrounding the anode and being approximately of the same height as the anode assembly, and provided with a slot parallel with and close to its bottom edge. Through the provision of this slot a thin strip is formed between the slot and the bottom edge or the spacer, which without being severed from the rest 01' the spacer, can easily be bent into a loop to be interposed between the anode and the bottom of the container. The anode thereby rests on the loop, which on one hand prevents the anode from accidental contact with the container bottom, and on the other hand helps to flx the spacer and prevent its displacement.

My invention will be further described by ref-. erence to the appended drawing, in which:

Figure 1 is a cross-sectional side view-of a condenser provided with a spacer in accordance with the invention;

Fig. 2 is a cross-sectional bottom view of Fig. 1 taken along the line 2-2; and

I Fig. 3 shows the slotted spacer in development.

Referring to the drawing, the-condenser shown therein comprises a cylindrical metallic container l0, which preferably constitutes its cathode and whichmay be either of film-forming or non-film forming metal. The container I0 is' provided with a reduced tubular extension l2, threaded at 20 and extending into a further reduced tubular portion 2!.

The anode assembly 28 as shown, consists of a thin foil 29 or aluminum or other film-forming metal, having the shape of an accordion pleating, and is suitably secured, for example, by meansof welding or by rivets, to an anode riser 30. The riser 30 consists of a straight rod of rectangular or cylindrical shape and projects with its end 34 beyond the container portion II. The

anode riser 30 is preferably of aluminum or other film-forming metal.

The extension 2| has preferably the same inside diameter as the extension [2, so that the two form a common bore 22; the wall thickness of the extension 2| is however much less than that of the extension I2.

Placed in the bore 22 is a tightly-fitting plug 25 preferably of semi-hard vulcanized rubber through which passes the anode riser 30. Proper.

sealing between the plug 25 and the neck 2| may be obtained by fluting the portion 2|.

The top of the container is provided with a crowned metal cap l6, which fits into the container end l3. A vent gasket H of suitable material, for example, of wax-impregnated cloth, is interposed between the container l and the cap IS. The free edge of the cap I6, with the gasket l4 interposed, is crimped over a rim provided on the container ill.

The threads 20 are adapted to receive a nut (not shown) by means of which the condenser may be attached to a suitable base.

Interposed between the container l0 and the anode assembly 28 is a spacer 32, for instance of thin hard rubber provided with perforations 33 to permit free circulation of the electrolyte.

In accordance with the invention the spacer 32 is formed from a sheet of insulating material whose width is slightly greater than the inner circumference of the container i0 and whose height is somewhat greater than the height of the anode assembly, which in the example shown is only about half as high as the container Ill.

The spacer 32 is provided wih a slot 38 running parallel to its lower edge by means of which a flexible strip 35 is formed which is attached at its two ends to the rest of the spacer. The spacer 32 is folded around the anode assembly with the strip 35 folded inwardly, and the spacer portion 31 above the slot 38 folded outwardly. Between the folded portions 35 and 31 an elliptical opening 40 is formed through which passes the anode 'riser 30.

If the anode 29 is formed as an accordion pleating, as shown in the drawing, the spacer 32 is preferably formed as a semi-cylindrical shell having two straight portions 3536 substantially parallel to the length axis of the anode, said.

straight portions being connected by the intermediate folded portions 35 and 31. The cylindrical portion of the spacer contacts the adjacent portion of the container wall and the folded portion 31 is bent to abut the remaining portion of the wall along a line dividing it into two equal segments. The inwardly projecting loop portion 35 is snugly inserted between the anode assembly and the bottom of the container. The loop 35 is sufficiently long to project inwardly past the axis of the condenser to permit passage of the anode riser through the hole 40, which it forms with the outwardly bent fold 31.

If the anode assembly has a cylindrical contour the main body of the spacer is cylindrical,

u but the loop 35 is given the same shape as just explained.

' results.

In practice, I prefer to make the strip 35 from .125" to .25" high, so as to allow sufficient clearance between the anode and the bottom of the container.

The anode is submerged in the electrolyte ll whereby between the electrolyte level and the top of the container there is left a suflicient space to permit expansion of the electrolyte even if it should freeze. The electrolyte comprises as a rule salts, acids, or alkalies and a solvent; preferably a combination of a weak acid and a salt is used, for instance an electrolyte comprising borax and boric acid or ammonium borate and boric acid. However, various other acids and salts either alone or in combination give good For instance, aqueous solutions of phosphoric acid, citric acid, tartaric acid, and/or their salts are also suitable electrolytes, whereby the salts do not need to be those of the acid used.

While I have described my invention in connection with specific examples and in specific embodiments, I do not wish to be limited thereto, but desire the appended claims to be construed as broadly as permissiblein view of the prior art.

What I claim is:

1. An electrolytic condenser comprising an anode, a cathode container, and an insulating spacer between said cathode container and said anode, said spacer consisting of a sheet of flexible material surrounding saiu anode and comprising an integral strip independently flexed with respect to the rest of the spacer and folded to separate the bottom of the anode from the bottom of the container.

2. In an electrolytic condenser, an anode and a metal container, said anode having a height considerably less than the container, a thin spacer of a height substantially equal to that of the anode and surrounding the anode to separate it from the container, said spacer comprising a fold at its bottom portion interposed between the bottom of said anode and said container and a second fold above said first fold, said folds flexed independently from each other and from the rest of the spacer.

3. In an electrolytic condenser comprising an anode assembly and a cylindrical container, said anode assembly comprising an anode and an anode riser, a sheet of insulating material disposed between said anode and said container, said sheet comprising a fold disjoined from a portion of said sheet and integral with the remainder of said sheet, said fold and said portion flexed in opposite directions to form an opening through which the anode riser passes.

4. In an electrolytic device, an anode and a metal container, a spacer comprising a sheet of insulating material surrounding the anode to separate it from the container, said spacer comprising a fold disjoined from a portion of said sheet and integral with the remainder of said sheet, said fold interposed between the bottom of said anode and said container.

JOSEPH L. COLLINS. 

